Micrometer-calipers.



No.b 7|7,296. Patented Dec. 3o, |902,

r3 F. SPALDING. g Mlc'BoMETEn GALIPERs "Application led Feb. 6, 1902.\ (un Model.)

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UNITED Armi FRANK SPALDING, OF PROVIDENCE, RHODE ISLAND,.ASSIGNOR TO BROWN (it SHARPE MANUFACTURING COMPANY, OF PROVIDENCE, RHODE ISLAND.

MICRONI ETER-CALIPERS.

SPECIFICATION forming part of Letters Patent No. 717,296, dated December so, 190e. Application iiled February 6, 1902. Serial No. 92,882. (No model.)

To ctZZ whom t may concern:

Beit known that l', FRANK SPALDINe,a citizen of the United States, residing at Providence, in the county of Providence and State of Rhode Island, have invented a new and useful Improvement in Micrometer-Calipers, of which the following is a specification.

This invention has reference to anirnproved device for clamping the spindle of a micro- 1o meter caliper or gage.

Micromcter calipers or gages consist usually of a frame having an anvil at one end and a spindle partly screw-threaded and in screw-thread engagement withv the opposite r 5 end. These calipers or gages are used in the arts for the accurate measurement ofparts and are usually constructed to determine microscopic differences Within one onethousandth of an inch; When the accurate zo measurement has been taken by a micrometer caliper or gage, it isV desirable to lock the spindle, so as to retain the exact position of the same. To lock the spindle and maintain the same in the position when the measurementis taken, it is important that the spindle should not be rotated or moved longitudinally in the slightest degree, so that the measurement taken Will not be altered.

The invention consists in the peculiar and 3o novel construction of a split-spring clampingring and means for actuating the same, as will be more fully set forth hereinafter.

Figure l is aside view of a micrometercaliper, showing my improvement. Fig. 2 is 3 5 a sectional View of the part of the frame of the caliper in which the spindle is supported and the clamping device locked. Fig. 3 is a transverse sectional View of the frame on the line X X of Fig. 2, showing the clampingring and the means for operating the same. Fig. 4 is a perspective view of the part of the frame in which the spindle is supported and with which theV split ring'is connected. Fig. 5 is a perspective View of the split clamping-ring, showing the member interposed between the split ring and the* actuating-ring. Fig. 6 is a perspective View of the actuatingring.

In the drawings, a indicates the frame of `5o the micrometer-caliper; a the anvil', a2 the sleeve extending over the barrel.

spindle, a3 the bearing for the spindle, a4 the barrel, and d5 the sleeve, of a micrometercaliper in which the spindle a2 is usually in screw-thread engagement with the end of the barrel aand the sleeve a5 is connected with 55 the spindle, so as turn with the same, the The side of the barrel is usually graduated, and the beveled end of the sleeve is also graduated, as is shown in Fig. l. 6o

The split ring b is provided with the preferably semicylindrical projection b. The tangential plane surface b2 extends from the peripheral edge of the ring near the split b3 to the shoulder bf, forming a Wedge-shaped seat in which the member b5, preferably a roller, may be inserted when the split ringb is placed into the actuating-ring c, the peripheral surface of which is preferably milled. The split ring b when in the normal expanded condi- 7o tion fits the spindle a2 with a sliding fit and also fits into the actuating-ring cwith a sliding fit. The split ring b and the actuatingring c are preferably of the same thickness.

In connecting the clamping device to the caliper I prefer to drill a hole ce through the Wall of the bearing 0,3 of the spindle andlthenl cut a slot al of a Width equal to the thickness Vof the actuating-ring o through the portion of the frame forming the bearing a'for the 8o spindle, one side of which slot is on aline with the center of the hole a6. When the slot al is cut, the remaining portion of the hole d6 forms the concave seat c2. (Shown in p Fig. 4.) The split ring b may now be placed into the actuating-ring c, the member b5 in the wedge-shaped cavity between the split ring and the actuating-ring, as is shown in Fig. 3, and the assembled parts may be slid into the slot a7, with the projection b' in the 9o seat c2. The spindle is now placed in position, extending through the split ring, which ring is held against rotation.

I do not wish to confine myself to the exact construction of the parts, as these may be modied without materially effecting the op` eration of the device.

A micrometer-caliper provided with my improved locking or spindle-clamping device may when the `spindle has been adjusted in roo taking a measurement be locked securely without the possibility of disturbing the ad-` justment of the spindle by rotating the actuating-ring c, and thereby moving the member b5 on the plane b2 toward lthe split b3 to contract the ring and clamp it onto the spindle a2. The spindle may be released by the reverse movement of the actuating-ring c.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. The combination With the spindle of a micrometer-caliper, the bearing of the spindle, a transverse slot in the bearing and a cavity in the Wall of the bearing, of a split ring, a projection on the split ring, a tangential plane 0n the split ring, an actuating-ring inclosing the split ring, and a member operated by the actuating-ring and operating the split ring, as described.

2. In a micrometer-caliper, the combination with the frame of the caliper, the anvil, the spindle, the bearing for the spindle, and the micrometer mechanism, of the slot o7, the seat c2 in the Wall of one side of the slot, the split ring b, the projection b on one face of the split ring, the plane b2 and shoulder b4 on the split ring, the member b5, and the actuating-ring c', as described.

In testimony whereof Ihave signed my 3o name to this specification in the presence of two subscribing Witnesses.

FRANK SPALDING. Witnesses:

JOSEPH A. MILLER, B. S. WEBSTER. 

